Forget the old dispute between the Wagnerians and the Brahmins -- Wagnerians are still arguing among themselves over interpretations of Tristan und Isolde.

On Tuesday night, the Philharmonia Orchestra of London brought Maestro Guiseppe Sinopoli's vision of the "Prelude" and "Liebstod" to Eisenhower Auditorium. For those accustomed to the comparatively terse interpretations of conductors such as Leonard Bernstein and Herbert von Karajan, Sinopoli's Tristan was, to say the least, surprising.

Langsam und schmachtend (slow and yearning). These are Wagner's tempo markings for the "Prelude," and Sinopoli carried them to a new extreme --a painfully slow interpretation that ached with yearning.

The pain was exquisite.

When the "Prelude" is played at a quicker pace, the evolutionary nature of its melodic motion becomes apparent, but its dovetailing harmonies can become indistinguishable. Not so with Sinopoli; he savored every note, allowing the listener to agonize with each step of its evolution. The audience was squirming, languishing in unstable tonalities -- yearning for a resolution that would not come.

"I think," said Patrick Terenchen (senior-English), "that by deliberately allowing the tragedy to take precedence over the usual Wagnerian heroics, Sinopoli illustrated exactly why Wagner was cut out to compose Tristan."

The love-death could never have been performed this way with singers; but it was precisely the lack of singers that allowed --or, rather, demanded -- Sinopoli's deeper reading of the text through the music.

Some, however, found the "Prelude" laborious.

"It's like pulling out chewing gum," said Asa J. Berlin, host of WPSU's Afternoon Classics. "He's trying to see just how far he can stretch out each note."

There were times when the orchestra did not respond fully to Sinopoli's creeping baton, as if they too were a bit astonished by the tempo; nonetheless, the orchestra's execution was superb.

"From the first stifled moan of quenchless longing," Wagner writes in his description of the "Liebstod," "from the faintest tremor to unpent avowal of a hopeless love, the heart goes through each phase of unvictorious battling with its inner fever, till, swooning back up itself, it seems extinguished, as in death." What further justification need Sinopoli for his poignant vision of the unfulfillable?

The second Wagner piece of the night, the "Overture" from Die Meistersinger von Nurnberg, opened vigorously with Sinopoli bouncing on his toes as if to shake off Tristan's languor. With exhilarating freshness, the orchestra sustained its vigor through to the "Overture's" rousing conclusion.

Die Meistersinger -- thematically juxtaposed against Tristan -- seems an ironic choice for this program; however, for Sinopoli, who may identify with the innovative, defiant Walther, it may be a rather appropriate one.

The second half of the program was devoted to Brahm's Fourth Symphony in E minor. The intermission had obviously not sapped any of the Philharmonia's exuberance. While Sinopoli hopped on one leg, the orchestra leapt into the Allegro non troppo with youthful energy -- one might have said "abandon" had it not been for Sinopoli's sharp phrase-clipping, which the orchestra obeyed with military precision.

In the Andante moderato, Sinopoli showed incredible sensitivity to dynamics. Under a detached French horn and clarinet, the strings pulsed in what was certainly the most delicate pizzicato possible within the bounds of audibility -- a flawless calculation of Eisenhower's acoustics.

Under Sinopoli's guidance, the melody unfolded in beautiful "musical prose" (a term devised by Schoenberg to describe Brahm's progressive themes, which do not fall into symmetrical, predictable patterns). The Andante was a rare treat.

The Allegro giocoso was explosive and frolicsome; the brass section played with a jocund edge, setting off a delightfully clean and bright piccolo. "That flute was awesome," whispered someone in my row.

The last movement of the Fourth was an intense and stirring conclusion to the concert. Sinopoli had full mastery of the Philharmonia -- his lively, sweeping gestures inextricable from the music itself.